וַאֲחֵיהֶם֙ לְתֹ֣לְדוֹתָ֔ם תְּשַׁ֥ע מֵא֖וֹת וַחֲמִשִּׁ֣ים וְשִׁשָּׁ֑ה כָּל־אֵ֣לֶּה אֲנָשִׁ֔ים רָאשֵׁ֥י אָב֖וֹת לְבֵ֥ית אֲבֹתֵיהֶֽם׃ (ס)
and their brethren, according to their generations, nine hundred and fifty and six. All these men were heads of fathers’houses by their fathers’houses.
Read midrashic interpretation of I Chronicles 9:9: and classical rabbinic exegesis.